EUS-guided FNA biopsy of the muscularis propria of the antrum in patients with gastroparesis is feasible and safe

Quantification of Interstitial Cells of Cajal in the Gastric Muscle of Patients with Gastroparesis at Per-Oral Endoscopic Pyloromyotomy: A Novel Approach for Future Research in Pathogenesis of Gastroparesis

BACKGROUND

The role of Interstitial Cells of Cajal (ICC) in the pathogenesis of gastroparesis has been suggested by previous studies due to their involvement in the transmission of neuronal signaling to the smooth muscles of the GI tract. However, studies have been limited by the inability to obtain a gastric muscle sample, since routine endoscopy can only biopsy the mucosa. We present a new technique of muscle biopsy during per-oral endoscopic pyloromyotomy (GPOEM), a novel endoscopic procedure for treatment of gastroparesis.

PATIENTS AND METHODS

All enrolled patients had diagnosed gastroparesis and had biopsies of the muscular layer at the antrum/pylorus during POEM. All GPOEM procedures took place from August 2019 to December 2019. Various demographic, disease-related, and procedure-related data were collected from chart review. ICC in the biopsy specimen was examined and quantitated.

RESULTS

Through this method, we readily expose the gastric muscle of 21 patients through dissection of a gastric submucosal tunnel during GPOEM and provide reliable muscle sample for ICC quantification. Average number of ICC were higher in clinical responders (88 ICC ± 63 vs. 39 ICC ± 24, p = 0.02), defined as those who experienced significant improvement in nausea and vomiting symptoms after GPOEM.

CONCLUSIONS

This study provides a reliable novel biopsy method for safely biopsy gastric muscle for quantitating the number of gastric ICC in patients with gastroparesis. The number of ICC may be related to the outcome of GPOEM therapy. However, further studies with larger number of patients are needed to confirm the results.

Helicobacter pylori causes delayed gastric emptying by decreasing interstitial cells of Cajal

Helicobacter pylori (HP) infection is one of the most frequent bacterial infections in humans and is associated with the pathogenesis of gastric motility disorders such as delayed gastric emptying (DGE). Although HP infection is considered to delay gastric emptying, there has been little research on the underlying mechanism. Gastric motility involves interactions among gastrointestinal hormones, smooth muscle, enteric and extrinsic autonomic nerves and interstitial cells of Cajal (ICCs), and ICCs play an important role in gastrointestinal motility. Mutation or loss of stem cell factor (SCF) expression is known to reduce the number of ICCs or alter the integrity of the ICC network, contributing to gastrointestinal dysmotility. The aim of the present study was to investigate whether a reduction in ICCs contributes to the DGE caused by HP. A mouse model of HP infection was established and gastric emptying was compared between HP-infected and uninfected mice using the bead method. In addition, ICC counts and SCF expression levels in gastric tissue were evaluated using immunohistochemistry and western blotting, respectively. The results revealed that gastric emptying was significantly slower, the number of ICCs in gastric tissue was significantly reduced and the protein level of SCF in gastric tissue was significantly decreased in HP-infected mice compared with uninfected mice. Therefore, it may be concluded that HP reduced the number of ICCs by decreasing the expression of SCF protein in gastric tissue, thereby causing DGE.

Gastric linitis plastica due to signet-ring cell carcinoma with Krukenberg tumors diagnosed by endoscopic ultrasound-guided fine-needle aspiration

Gastric linitis plastica is a rare condition characterized by the stiffening and thickening of the gastric wall, presenting a "leather bottle" appearance. It is generally associated with infiltration of poorly differentiated gastric cancer cells, but similar findings can arise due to metastases from other cancers and benign inflammatory processes. Despite advances in imaging modalities, pathological evaluation is required for diagnosis. As endoscopic mucosal biopsies may not be diagnostic, endoscopic ultrasound-guided fine-needle aspiration of the thickened stomach wall presents a potential diagnostic option. We report a case which presented with bilateral ovarian tumors and was ultimately diagnosed as gastric signet-ring cell carcinoma with Krukenberg tumors by endoscopic ultrasound-guided fine-needle aspiration of the stomach wall. The preoperative diagnosis allowed the patient to avoid surgery and to start chemotherapy for gastric cancer. We also review the existing literature on endoscopic ultrasound-guided fine-needle aspiration in the context of gastric linitis plastica.

Gastric Biopsies in Gastroparesis: Insights into Gastric Neuromuscular Disorders to Aid Treatment

The cellular and molecular understanding of human gastroparesis has markedly improved due to studies on full-thickness gastric biopsies. A decrease in the number of interstitial cells of Cajal (ICC) and functional changes in ICC constitutes the hallmark cellular feature of gastroparesis. More recently, in animal models, macrophages have also been identified to play a central role in development of delayed gastric emptying. Activation of macrophages leads to loss of ICC. In human gastroparesis, loss of anti-inflammatory macrophages in gastric muscle has been shown. Deeper molecular characterization using transcriptomics and proteomics has identified macrophage-based immune dysregulation in human gastroparesis.

Submucosal Tunneling Muscle Biopsy for Esophageal Motility Disorders: A Case Report

Submucosal tunneling endoscopic technique can be useful in obtaining esophageal muscle specimens in patients with esophageal motility disorders. Here, we describe the case of a patient with systemic sclerosis. Histological verification of the esophageal involvement in the pathological process was required for the treatment. There were no intra- and post- operational complications.

Effectiveness of gastric electrical stimulation in gastroparesis: Results from a large prospectively collected database of national gastroparesis registries

BACKGROUND

Gastric electrical stimulation (GES) for treating gastroparesis symptoms is controversial.

METHODS

We studied 319 idiopathic or diabetic gastroparesis symptom patients from the Gastroparesis Clinical Research Consortium (GpCRC) observational studies: 238 without GES and 81 with GES. We assessed the effects of GES using change in GCSI total score and nausea/vomiting subscales between baseline and 48 weeks. We used propensity score methods to control for imbalances in patient characteristics between comparison groups.

KEY RESULTS

GES patients were clinically worse (40% severe vs. 18% for non-GES; P < .001); worse PAGI-QOL (2.2. vs. 2.6; P = .003); and worse GCSI total scores (3.5 vs. 2.8; P < .001). We observed improvements in 48-week GCSI total scores for GES vs. non-GES: improvement by ≥ 1-point (RR = 1.63; 95% CI = (1.14, 2.33); P = .01) and change from enrollment (difference = -0.5 (-0.8, -0.3); P < .001). When adjusting for patient characteristics, symptom scores were smaller and not statistically significant: improvement by ≥ 1-point (RR = 1.29 (0.88, 1.90); P = .20) and change from the enrollment (difference = -0.3 (-0.6, 0.0); P = .07). Of the individual items, the nausea improved by ≥ 1 point (RR = 1.31 (1.03, 1.67); P = .04). Patients with GCSI score ≥ 3.0 tended to improve more than those with score < 3.0. (Adjusted P = 0.02).

CONCLUSIONS AND INFERENCES

This multicenter study of gastroparesis patients found significant improvements in gastroparesis symptoms among GES patients. Accounting for imbalances in patient characteristics, only nausea remained significant. Patients with greater symptoms at baseline improved more after GES. A much larger sample of patients is needed to fully evaluate symptomatic responses and to identify patients likely to respond to GES.

Gastroparesis syndromes: Response to electrical stimulation

BACKGROUND AND AIMS

Factors underlying gastroparesis are not well defined, nor is the mechanism of action of gastric electrical stimulation (GES). We hypothesized that GES acts via several mechanisms related to underlying disordered pathophysiology.

METHODS

We studied 43 consecutive eligible patients with gastroparetic symptoms, previously evaluated by two methods in each of five core areas: inflammatory, autonomic, enteric, electrophysiologic, and hormonal; and also categorized by GI symptoms, metabolic status, illness quantification, and gastric physiology. We then studied 41 patients who underwent temporary GES for 5-7 days. Thirty-six of those patients were implanted and 30 were followed up at 6 months after permanent GES.

RESULTS

In previous but separately reported work, patients had similar GI symptoms regardless of baseline gastric emptying or diabetic/idiopathic status and all patients demonstrated abnormalities in each of the five areas studied. After GES, patients showed early and late effects of electrical stimulation with changes noted in multiple areas, categorized by improvement status.

CONCLUSION

Patients with symptoms of gastroparesis have multiple abnormalities, including systemic inflammation and disordered hormonal status. GES affects many of these abnormalities. We conclude electrical stimulation improves symptoms and physiology with (a) an early and sustained anti-emetic effect; (b) an early and durable gastric prokinetic effect in delayed emptying patients; (c) an early anti-arrhythmic effect that continues over time; (d) a late autonomic effect; (e) a late hormonal effect; (f) an early anti-inflammatory effect that persists; and (g) an early and sustained improvement in health-related quality of life. This study is registered with Clinicaltrials.gov under study # NCT03178370 (https://clinicaltrials.gov/ct2/show/NCT03178370).

Endoscopic techniques for full thickness intestinal biopsy

PURPOSE OF REVIEW

Accurate diagnosis of gastrointestinal neuromuscular diseases requires full thickness biopsy for adequate histologic evaluation of the enteric neuromuscular and ancillary cells. Historically, this has been achieved by surgical approaches. An overview of procedure evolution and current techniques of endoscopic full thickness biopsy (EFTB) for diagnosis of gastrointestinal neuromuscular disorders will be presented.

RECENT FINDINGS

Emergence and advancement of endoscopic full thickness resection techniques has offered a less invasive, nevertheless an effective modality of tissue acquirement. Recently, clip-assisted close-then-cut EFTB has been utilized in clinical practice under research protocol. Early experience has shown that this technique provides an adequate full-thickness specimen including the myenteric plexus and ganglia cells, with acceptable safety profiles.

SUMMARY

EFTB is a promising means in diagnosing the nature of the disease and guiding therapy. Available animal and human studies have shown the noninferiority of endoscopic methods to surgical ones in term of adequacy of tissue samples, while potentially decreasing the risk and occurrence of complications. Further large prospective studies are needed to assess its efficacy, safety and impacts on patient's outcomes.

A quarter century of EUS-FNA: Progress, milestones, and future directions

Tissue acquisition using EUS has considerably evolved since the first EUS-FNA was reported 25 years ago. Its introduction was an important breakthrough in the endoscopic field. EUS-FNA has now become a part of the diagnostic and staging algorithm for the evaluation of benign and malignant diseases of the gastrointestinal tract and of the organs in its proximity, including lung diseases. This review aims to present the history of EUS-FNA development and to provide a perspective on the recent developments in procedural techniques and needle technologies that have significantly extended the role of EUS and its clinical applications. There is a bright future ahead for EUS-FNA in the years to come as extensive research is conducted in this field and various technologies are continuously implemented into clinical practice.

Diabetic and idiopathic gastroparesis is associated with loss of CD206-positive macrophages in the gastric antrum

BACKGROUND

Animal studies have increasingly highlighted the role of macrophages in the development of delayed gastric emptying. However, their role in the pathophysiology of human gastroparesis is unclear. Our aim was to determine changes in macrophages and other cell types in the gastric antrum muscularis propria of patients with diabetic and idiopathic gastroparesis.

METHODS

Full thickness gastric antrum biopsies were obtained from patients enrolled in the Gastroparesis Clinical Research Consortium (11 diabetic, 6 idiopathic) and 5 controls. Immunolabeling and quantitative assessment was done for interstitial cells of Cajal (ICC) (Kit), enteric nerves protein gene product 9.5, neuronal nitric oxide synthase, vasoactive intestinal peptide, substance P, tyrosine hydroxylase), overall immune cells (CD45) and anti-inflammatory macrophages (CD206). Gastric emptying was assessed using nuclear medicine scintigraphy and symptom severity using the Gastroparesis Cardinal Symptom Index.

RESULTS

Both diabetic and idiopathic gastroparesis patients showed loss of ICC as compared to controls (Mean [standard error of mean]/hpf: diabetic, 2.28 [0.16]; idiopathic, 2.53 [0.47]; controls, 6.05 [0.62]; P=.004). Overall immune cell population (CD45) was unchanged but there was a loss of anti-inflammatory macrophages (CD206) in circular muscle (diabetic, 3.87 [0.32]; idiopathic, 4.16 [0.52]; controls, 6.59 [1.09]; P=.04) and myenteric plexus (diabetic, 3.83 [0.27]; idiopathic, 3.59 [0.68]; controls, 7.46 [0.51]; P=.004). There was correlation between the number of ICC and CD206-positive cells (r=.55, P=.008). Enteric nerves (PGP9.5) were unchanged: diabetic, 33.64 (3.45); idiopathic, 41.26 (6.40); controls, 46.80 (6.04).

CONCLUSION

Loss of antral CD206-positive anti-inflammatory macrophages is a key feature in human gastroparesis and it is associates with ICC loss.

The Long-Term Efficacy and Safety of Pyloroplasty Combined with Gastric Electrical Stimulation Therapy in Gastroparesis

INTRODUCTION

Gastroparesis is delayed gastric emptying without mechanical obstruction. Symptomatic improvement can be 50-60% with gastric electrical stimulation. To address delayed gastric emptying, pyloroplasty was added. This study examines the long-term efficacy and safety of simultaneous gastric electrical stimulator implantation and pyloroplasty.

METHODS

In this prospective single-arm trial conducted from 2012 to 2015, 27 [23 females; mean age 43 (22-63)] gastroparesis patients who underwent simultaneous gastric electrical stimulator implantation with Heineke-Mikulicz pyloroplasty were studied. Six (25%) underwent simultaneous robot-assisted pyloroplasty and gastric electrical stimulator implantation. Diagnosis of gastroparesis was based on the 4-h gastric emptying test defined as >60% retention of isotope at 2 h and >10% at 4 h. Total symptom scores assessing severity of nausea, early satiety, bloating, vomiting, post-prandial fullness, and epigastric pain were obtained at baseline and at follow-up visits, ranging from 3 to 38 months (mean: 17).

RESULTS

Follow-up data from 24 patients were available for analysis. There was 71% improvement in total symptom score on follow-up. Mean retention decreased by 29.6 and 48.7% at 2 and 4 h and gastric emptying was normalized in 60%. There were no post-surgical complications.

CONCLUSIONS

Combination of gastric electrical stimulator and pyloroplasty significantly accelerated gastric emptying and improved gastroparesis symptoms. Combining these two surgical therapies improves both subjective and objective endpoints in drug refractory gastroparesis.

Innovative gastric endoscopic muscle biopsy to identify all cell types, including myenteric neurons and interstitial cells of Cajal in patients with idiopathic gastroparesis: a feasibility study (with video)

BACKGROUND AND AIMS

The pathophysiology of some GI neuromuscular diseases remains largely unknown. This is in part due to the inability to obtain ample deep gastric wall biopsies that include the intermuscular layer of the muscularis propria (MP) to evaluate the enteric nervous system, interstitial cells of Cajal (ICCs), and related cells. We report on a novel technique for gastric endoscopic muscle biopsy (gEMB).

METHODS

Patients with idiopathic gastroparesis were prospectively enrolled in a feasibility study by using a novel "no hole" gEMB. Main outcome measures were technical success, adverse events, and histologic confirmation of the intermuscular layer, including myenteric neurons and ICC. The gEMB was a double resection clip-assist technique. A site was identified on the anterior wall of the gastric body as recommended by the International Working Group on histologic techniques. EMR was performed to unroof and expose the underlying MP. The exposed MP was then retracted into the cap of an over-the-scope clip. The clip was deployed, and the pseudopolyp of MP created was resected. This resulted in a no-hole gEMB.

RESULTS

Three patients with idiopathic gastroparesis underwent gEMB. Patients had severe delayed gastric emptying with a mean (± standard deviation [SD]) of 49 ± 16.8% of retained gastric contents at 4 hours. They had no history of gastric or small-bowel surgery and did not use steroids or other immunosuppressive drugs. The gEMB procedure was successfully performed, with no procedural adverse events. Postprocedural abdominal pain was controlled with nonsteroidal anti-inflammatory agents and opioid analgesics. Mean length of resected MP was 10.3 ± 1.5 mm. Mean procedure time was 25.7 ± 6 minutes. Hematoxylin and eosin (H&E) staining of tissue samples confirmed the presence of both inner circular and outer longitudinal muscle, as well as the intermuscular layer. H&E staining showed reduced myenteric ganglia in 1 patient. In 2 patients, specialized immunohistochemistry was performed, which showed a marked decrease in myenteric neurons as delineated by an antibody to protein gene product 9.5 and a severe decrease in ICC levels across the muscle layers. At 1 month follow-up, upper endoscopy showed a well-healed scar in 2 patients and minimal ulceration with a retained clip in 1 patient. CT of the abdomen confirmed the integrity of the gastric wall in all patients. Because of lack of an immune infiltrate in the resected samples, patients were not considered suitable for immunosuppressive or steroid therapy.

CONCLUSIONS

gEMB is feasible and easy to perform, with acquisition of tissue close to surgical samples to identify myenteric ganglia, ICCs, and multiple cell types. The ability to perform gEMB represents a paradigm shift in endoscopic tissue diagnosis of gastric neuromuscular pathologies.

Eosinophilic esophageal myositis diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsy: a case report

Eosinophilic esophagitis (EoE) is diagnosed by microscopic findings of eosinophilic infiltration into the squamous epithelium. In contrast, another disease concept termed "eosinophilic esophageal myositis (EoEM)" has been proposed, whereby there is eosinophilic infiltration into the muscularis propria instead. A 60-year-old man was referred to our hospital for chest pain, dysphagia, and several episodes of esophageal food impaction. Although EoE was suspected based on clinical features, biopsy specimens showed no mucosal eosinophilic infiltration. Endoscopic ultrasound (EUS) showed thickening of the muscularis propria layer and subsequent EUS-guided fine-needle aspiration biopsy (EUS-FNA) revealed eosinophilic infiltration into the muscularis propria. Although the patient's symptoms gradually improved after steroid administration, complete remission was not achieved after 1 year of treatment. This case may reflect a disorder distinct from typical EoE based on eosinophilic infiltration of the muscularis propria but not the squamous epithelium, and we, therefore, diagnosed it as EoEM using the EUS-FNA findings as reference.

Is Interstitial Cells of Cajal‒opathy Present in Gastroparesis?

Gastroparesis (GP), defined as delayed gastric emptying in the absence of any mechanical obstruction, is a challenging clinical condition, mainly because of limited treatment options. Studies in animal models of delayed gastric emptying as well as patients with gastroparesis revealed depletion or ultrastructural changes of interstitial cells of Cajal (ICC) in the gastric tissue, recently termed ICC-opathy. ICC are the pacemakers of the gastrointestinal tract and are involved in the transmission of the neuronal signaling to the smooth muscles. Therefore, lack of ICC could be one explanation of delayed gastric emptying in gastroparetic patients. How frequently ICC changes are observed in gastroparesis is not yet clear. In this review, the data on gastric ICC counts and morphology in animal models and patients with gastroparesis are discussed.